The present invention relates an apparatus and method for controlling the driving force of an automotive vehicle to achieve a four-wheel drive state.
Japanese Laid-Open Patent Publication No. 2000-318473 proposes one type of four-wheel drive vehicle, which has an engine drivingly connected to main drive wheels of the vehicle, a motor drivingly connected to subsidiary drive wheels of the vehicle and a generator driven by the engine to supply power to the motor so as to achieve a four-wheel drive state of the vehicle. In this proposed structure, the vehicle does not necessarily require a battery as a power source of the motor.